This can be seen below: Unused Directories can be deleted using the 'rmdir'.

The subdirectory named 'Extra' can be deleted using 'rmdir Extra' as shown below

Permissions can be granted on the command line using the 'chmod' command.

r, w and x refers to read, write and execute permission u, g and o refers to user (owner), group (accountant) and o (others)

+ is used for granting permission

Is used to deny permission.

chmod u+rwx Extra -- Grants all permissions for the 'Extra' subdirectory to the user (owner)

chmod g+rwx Extra - Grants all permissions for the 'Extra' subdirectory to the group (accountant)

chmod g+rwx Extra - Denies all permissions for the 'Extra' subdirectory from the others.

Subdirectories with files inside them can be deleted using the 'rm -- rf' command.

The subdirectory 'Extra' with a text file...

It can also be done using the command 'vi CustDetails.txt'
The details as seen on the GUI is shown below

The file 'CustDetails.txt' can be displayed on the Command Line using the command 'cat CustDetails.txt' as shown below.